Studying animal tissue such as those of Hydra – an animal full of active stem cells during all its life – may deliver valuable insight into stem cell ageing as such.

„Surprisingly, our search for the gene that causes Hydra to be immortal led us to the so-called FoxO gene“, says Anna-Marei Böhm, PhD student and first author of the study. The FoxO gene exists in all animals and humans and has been known for years. However, until now it was not known why human stem cells become fewer and inactive with increasing age, which biochemical mechanisms are involved and if FoxO played a role in ageing.

FoxO has been found to be particularly active in centenarians – people older than one hundred years – which is why we believe that FoxO plays a key role in ageing – not only in Hydra but also in humans“. However, the hypothesis cannot be verified on humans, as this would require a genetic manipulation of humans.

Centagen is a biotechnology company that is developing medical therapies that utilize a patient's own adult stem cells. The company has a new technology to expand adult stem cells in vitro (in the lab) up to 1 million times, then rejuvenate them and inject the stem cells back into the person from which they came. This will help repair and rejuvenate organs and tissues damaged by aging, disease and injury. The process may even help healthy people stay young.

They can multiply the rare adult stem cells in cell culture without aging them or degrading their function. One innovation involves lengthening the telomeres while amplifying the stem cells.

Mice treated at the age of one lived longer by 24% on average, and those treated at the age of two, by 13%. The therapy, furthermore, produced an appreciable improvement in the animals' health, delaying the onset of age-­‐related diseases -- like osteoporosis and insulin resistance -- and achieving improved readings on aging indicators like neuromuscular coordination.

The gene therapy consisted of treating the animals with a DNA-­modified virus, the viral genes having been replaced by those of the telomerase enzyme, with a key role in aging. Telomerase repairs the extreme ends or tips of chromosomes, known as telomeres, and in doing so slows the cell's and therefore the body's biological clock. When the animal is infected, the virus acts as a vehicle depositing the telomerase gene in the cells.

This study "shows that it is possible to develop a telomerase-­based anti-­aging gene therapy without increasing the incidence of cancer," the authors affirm. "Aged organisms accumulate damage in their DNA due to telomere shortening, [this study] finds that a gene therapy based on telomerase production can repair or delay this kind of damage," they add.